Process for recovery of juice from sucrose bearing materials



July 20, 1965 A. w. FRENCH 3,195,446

PROCESS FOR RECOVERY OF JUICE FROM SUGROSE BEARING MATERIALS Original Filed July 9, 1957 4 Sheets-Sheet 1 INVENTOR ALFRED W. FRENCH ATTORNEYS July 20, 1965 w, FRENCH 3,195,446

PROCESS FOR RECOVERY OF JUICE FROM SUCROSE BEARING MATERIALS Original; Filed July 9, 1957 4 Sheets-Sheet 2 M g ATTOR lzI-LYS July 20, 1965 A. w. FRENCH 3,

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PROCESS FOR RECOVERY OF JUICE FROM SUCROSE BEARING MATERIALS Original Filed July 9, 1957 4 Sheets-Sheet 4 FIG-9 r INVENTOR ALFRED w. FRENCH ATTORNEYS FIG-7 United States Patent M 3,195,446 PROCESS FOR REQGVERY 0F .lUl CE FRGM SUCRGSE BEARING MATERIALS Alfred W. French, Piqua, Ohio, assignor to The French Oil Mill Machinery Company, Piqua, Ohio, a corp0ra= tion of Ohio Original appiication July 9, 1957, Ser. No. 670,743, now Patent No. 3,086,452, dated Apr. 23, 1%3. Divided and this application Nov. 30, 1%2, Ser. No. 241,399

9 Claims. (Cl. 1100-37) This application is a division of copending application Serial No. 670,743 fi-led July 9, 1957, now Patent No. 3,086,452 issued April 23, 1963.

A primary object of this invention is the provision of a process for expressing juice from sugar cane in which a high percentage of the cane juice is expressed from the cane through the substantially continuous application of high mechanical pressure, and in which the bagasse fiber is [discharged with a low retained moisture content Another object of this invention is to provide a process for expressing juice fromsugar cane in which the cane is defibered and the fibers mixed under sustained pressure to contribute to further expression of juice.

Another object of this invention is the provision of a process for expressing juice from sugar cane in which the cane is frictionally heated during its movement through the expressing apparatus while under a high mechanical pressure to promote further removal of the juice from the cells.

Another object of this invention is the provision of a process for recovering high percentage of the sucrose content of sugar cane through the use of a maceration fluid intermediate expressing stages.

Other objects and advantages of the present invention will be apparent from the following description, the accompanying drawings and the appended calims.

In the drawings- FIG. 1 is a somewhat schematic side elevation of apparatus used to carry out the present process;

FIG. 2 is a sectional side elevation of that portion of the apparatus which is used to prepare the cane for its primary juice expressing operation;

FIG. 3 is an in part sectional and in part full side elevation of a press used in conjunction with the cane preparing means of FIG. 2 to express juice from sugar cane;

FIG. 4 is a sectional side elevational view showing shredding means for cutting raw cane to suitable lengths;

FIG. 5 shows schematically the application of crushing rolls to prepare raw cane for entry into the expressing apparatus;

FIG. 6 is a fragmentary sectional view taken substantially along the line 66 of FIG. 3 and showing the screen bar cage structure;

FIG. 7 is a schematic elevation of a roll type expressing mill with an interrupted flight screw press positioned at the discharge end to receive bagasse and express additional fluid therefrom;

FIG. 8 is a schematic side elevation of two interrupted flight screw type expressing presses arranged in series with maceration fluid added between two presses; and

FIG. 9 is a slightly enlarged fragmentary showing of the restricting orifice of FIG. 3 with a manifold for adding maceration fluid to the fibrous material as it passes through the orifice.

Successful commercial recovery of the sucrose found in sugar cane juice depends upon expression of the cane juice from the cane within the reasonably limited period of time when the percentage of sucrose present is at a maximum. Sugar cane, in some cases, decreases in sucrose content if permitted to stand in the field and overripen. On the other hand, if the cane is cut and not 3,.iii5fi4h Patented July 20, lfi5 processed within a short time the sucrose content will further decrease due to partial inversion thereof. Thus, due to the critical nature of the time period within which the cane must be worked to obtain the maximum sucrose recovery, can mills are normally constructed to handle relatively large quantities of raw cane Within a short period of time. Naturally any time the mill is forced to shut down to make repairs because of mechanical failures, valuable sucrose may be lost and the recovery operation become less efiicient.

Present sugar cane processing factories, utilizing rollertype mills to effect crushing of the cane to express the juice therefrom, normally use sizeable quantities of maceration water intermediate successive crushing stages to achieve efficient recovery of the sucrose content.

The present invention, in many instances, makes possible the recovery of sucrose percentages approximately equivalent to those now obtained without the use of maceration or l-ixiviating liquids, as well as reducing the chances of sucrose loss occurring from interrupted mill operations in factories where one piece of machinery depends upon another. The present process and apparatus are also capable of utilizing maceration fluids in those instances where it is either desired or preferred. Since the present apparatus effects expression of the juice independently of any other apparatus, when a plurality of such devices are used they may be arranged to operate in parallel to handle the entire amount of cane being processed by the mill and the breakdown of one piece of apparatus will in no way affect the independent functioning of those remaining.

While the present invention will be hereinafter described with particular reference to the treatment of sugar cane, it also provides substantial advantages in handling other sucrose bearing fibrous material such as, tor example, sugar beets and sorghum. Related apparatus and method for specific application in recovering increased quantities of sucrose from sugar cane, and more particularly from the trash or cush-cush fibers formed during the pressing operation, and otherwise improving the efficiency of existing extraction processes are described and claimed in copending application Serial No. 670,742 (now Patent No. 3,037,445) filed of even date with copending application Ser. No. 670,743 (now Patent No. 3,086,452) and assigned to the same assignee as the present application.

Referring now to the drawings which illustrate preferred embodiments of apparatus for elfectuating the present process, a generally horizontally disposed conveyor (FIG. 1), driven by a motor 1 1, is provided for transportation of raw cane 12 into a cane chopper 15 where a feeding conveyor belt 16 can advance it into a rotary cutting mechanism 17 having a plurality of cutting blades :18 arranged around the periphery thereof. An upwardly inclined conveyor 19 positioned below blades 18 receives the chopped cane and dumps it into a cone-shaped hopper 243 which is protected by a cone cover 21. Conveyors 116 and 19 are driven by the motor 22 illustrated diagrammatically in FIG. 1, while cutting mechanism 17 is driven by motor 23.

Frame work 25 provides support for hopper 2t} and also for a driving motor 26 which has its pulley 27 (FIG. 2) connected to the input shaft 28 of a gear box 319 by means of a belt 31. The output shaft 32 (FIG. 2) of the gear box is operatively joined to the shaft 33 of a screw conveyor 35 through the connecting spline 36. The upper portion of shaft 33 Carries a continuous feeding vane 37 to move cane from hopper 2d, while that portion of shift 33 extending beyond the lower limit of hopper 20 carries a series of interrupted feeding vane flights 40 which have spaces 41 between the adjacent ends of successive flights.

A vertically disposed expression cage 45 surrounds the interrupted vane flights 40 of screw conveyor 35 and includes a plurality of vertically disposed, radially spaced.

screen bars 46 (FIG, 2); which are held in place by wedge bars 47, the wedge bars being adjustably secured to cage adjustably secured to force feed cage' 45, through holdv 7 ing strip 56, as by bolts'57. The adjustable fasteners 53 V on the, outer ends of the breaker bars provide means for 4 A preliminary expression cage 100 begins at vertically extending wall 70 and surrounds a portion of feed worm 84 and screw flight 85 to define a preliminary expression zone-101; Cage 100 includespush-through-type breaker bars 105, the breakerbars being adjustably secured to a holding strip 106 through adjustable fasteners 107.. Screws 108 are then used to mount the holding strip 106 to the cage proper.

' collars are located inwardly thereof. The areas between adjusting them radially into or out of the chamber 51 the collars and the expression cage120 define-zones 121 within the vertical spaces 41 between interrupted vanes where primarily compactingand expression occur while 40 to stop rotary movement of the cane in the chamber the areas between the worm flights and the cage 120 and cause it to move axially downwardly therethrough. define zones 122'where primarilydefiberingoccurs. Ex- Expression cage 45 is enclosed within an imperforate pression cage 120 includes screen bars 125 with drainage wall 66) which receives the expressed juice and directs it openings obtainableby means of vspacers 123 and breaker downwardly into a collecting trough' 61 adjacent the bars 126, which have a plurality of longitudinally and lower end of the cage structure-Where the juice can be radially extending lugs 12 7 terminating just short of the Withdrawn through outlet valve 62 to any suitable collecouter surface of pressure collars 86, 88, 90, 92 and 94 tion receptacle. 7 p s and discharge -cone% to cause primary longitudinal A ring-like split cone 65, positioned adjacent the lower movement of. cane over-these collars without the presence end of expression cage 45, has a tapered inner surface of excessive rotary motion. Reinforcing structure 130 is defining a restricting orifice 66 of less diameter than the present to strengthen the screen bar sections since large diameter of chamber 51. A clamping ring 67 of slightly radial forces .are exerted against them when the press greater height than split ring 65 surrounds the split ring is operating; T to hold it together and in :operating position; Beneath f Satisfactory results have been obtained, reducing the restricting orifice 66 arverticallyextending wall 70 defines; moisture content of sugar cane to: as low as 30%, with a further chamber 71, of greater diameter than the orifice, a press having a cage inner diameter of 8 /2 inches and where the cane is permitted to expand as it, drops into having case hardened steelpressure collars and screw press inlet chamber 72 (-FIG. 3). vSuch collararrange- 'flights. of the followingdirnensions. Screw fiightsand ment is described and claimed in more detail in copending pressure .collars 92 95 'inclusive have been omitted in application, Serial No. 645,165 filed March 11, 1957, this example. 1

Table '1 Screw Flights and V l V l a Pressure Collars 85 86 87 V 88 89 90 91 96 Diameters in inches i 5M0 5%6-6 /2 6A 6%6 6% (SM-7% 6% 6 47% Length in inches 4% E 4% 4% 4% 42$ 3% 4% 10% now Patent No. 3,067,672, and assigned to the same as- Higher pressures can be obtained by either using longer signee as the present application. j I collars or collars and worms of larger diameters should A suitable drivemotor 74, partof which is shown in such higher pressure be needed or preferred. l FIG. 1, is mounted on a gear housing 75. Housing 75, The metals from which thepress components are concontaining a pair of driven gears 76 and 77 (FIG. 3), is structed are also significant when determining the dimenmounted adjacent the wall 70, with gear 76 operably consions of the components which can be usedto obtain satisnected through a driving sleeve 78 to a longitudinally factory results. For example, aStellite coating will deextending shaft80, as by spline connection 81, and gear crease the friction between theseparts and the cane mate- 77 operably.connectedthrough a sleeve 82 and dog 83 rial and thereby makechanges in press dimensions advisto a feed screw 84 which surrounds a portion of shaft able, if the most eflicient operating forces are to be oband extends longitudinally through inlet chamber 72. tained; Stellite is a series'of alloys comprising cobalt- Gears 76 and 77 are driven through a suitable connection chromiun tungsten which are manufactured by Union with motor 74, with gear 77 preferably being operable. at Carbide & Carbon Company. A press using Stellite, omita higher speed than gear 76 so that feed screw 84rnay 6O ting screw'flight 85 and pressure'lcollar 86, could have the be rotated faster than shaft 80. Following feed screw 84 remaining pressure collars and screw flights dimensioned a plurality of alternately arranged screw flights 85, 87, as shown in Table 2. i l v Table 2 Screw Flights and l l Pressure Collars s7 as 89 F 90 r 91 92 93 V 94 r 95 96 Diameters in inches 5M0 5%6-614 5M6 EMga-Gld 6% (344% 6A 6M-7l-i 6% 6%7 /-i Length in inches 4% 4 6 4% 4% 4% 3% 4% 3 ,4 4% 5A 89, 91, 93 and 95 and pressure collars 86, 88, 90, 92 and The end structure surrounding the remainder of 94 and a final discharge collar 96 are all keyed or othershaft 80 beyond discharge cone 96'includes a cylinder 136 wise suitably attachedto the shaft- 80 for rotation there- 75 which controls the size of the outlet opening 140.

with.

' To collect juice as it is expressed from the cane in the preliminary and main expression zones ltd and lid, respectively, the press has a hollow supporting base 145 which defines a juice collecting chamber 146. As the juice is extracted through the expressing cage structure it drops to chamber 146 and flows through outlet opening 147 to a place of collection.

In certain instances it may be preferred that the raw cane be reduced in size by other means than chopper 15. Due such means is the shredding apparatus shown in FlG. 4, where raw cane is cut by shredding members 151 carried on a rotatable member 152. As cane is fed into shredder 159 it is cut by members ESQ-l, forced t trough the grid formed by bars 1% and reduced to a somewhat finer physical condition than is the case in the chopper-type cutter. After the cane passes bars 153 it falls into conveyor 155 which moves it into the hopper it for subsequent treatment.

A second cane cutting arrangement is provided by the crushing rolls 160 shown schematically in FIG. 5, which have a plurality of teeth 1% that crush or tear the cane into the desired sizes as it is passed between them toward hopper 26.

FIG. 9 illustrates another manner in which sucrose bearing fibrous material can be subjected to serial cornpacting operations with the addition of maceration fluid between the expressing steps. Specifically, screw press arrangement 17% which is analagous to the feeding arrangement utilizing cage of FIG. 2, has a ring-like split cone 171 and clamping ring 172 which serve the same function as their counter parts of FIG. 2. In this case however a fluid injection manifold 173 is positioned beneath members 1'71 and 172 to supply fluid to the sucrose bearing material as it passes beyond the restricted opening defined by ring 1'71. in this manner the cane is subjected to free moisture at a time when it is expanding, and free of any large restraining pressure so that it can readily absorb moisture.

Generally the present process for expressing juice from sugar cane comprises feeding raw cane 11; into cutting means 15 where it is reduced in size by chopping, shredding, or crushing, depending upon the form of cutting apparatus used, and fed by conveyor 19 into the cane hopper 20. A series of revolving cane knives, for example, mounted to cut or chop the cane as it moves on the conveying means is a good method for reducing the size of the raw cane. Once within hopper 2d the cane feeds downwardly through the action of feed worm 3-5 into the vertically arranged expression cage 45. As the screw attempts to advance the cane through restricting orifice 66, a back pressure is built up in the cane within the cage. The mechanical pressure thus exerted against the cane causes a rupturing of the juice containing cells contained in the sugar cane fibers with a consequent initial expression of juice through the spacings between cage bars to.

After passing through restricting orifice 66 the partially expressed cane material can either be treated with a maceration fluid from manifold 1 53 as it is expanding and extremely receptive to absorption of the fluid or, if the manifold is not used, can continue through further chamber "ilwhere the pressure is released and the material allowed to expand to substantially its original size without the addition of fluid. After chamber 713. the material enters press inlet chamber 72 where feed Worm 3d moves it longitudinally toward the press inlet. Since feed Worm 84 is driven by gear '76 at a higher rate of speed than the press screw flights are driven by gear 77 the cane is once again coinpacted, this time in the area defined by preliminary expression cage lltlil. This second compacting achieves a second expression of juice from the came, the juice flowingoutwardly through the cage to chamber 146.

The first screw flight 85 takes the compacted cane from cage res and moves it inwardly toward pressure collar 86 in a generally helical path which creates a defibering action under pressure with mixing of the fibers to achieve a reorientation of the cellular structure. Re-

orientation contributes to further expression of juice as the cane is forced over the collar 86, where a crushing or expressing action occurs. Screw flight 87 operates in much the same manner as screw flight in that it takes compacted material from an expressing zone, viz., that zone between collar 36 and screen bar section 115, and defibers and mixes the fibers while moving them onward toward collar 88. The worms and collars following worm $7 and collar 88 operate on the cane in the same manner except that the increased body diameters of worm and discharge cone 96 cause a greater packing of the cane at the outlet end of the press.

Using a press of the dimensions set forth in Table 1, it has been found that sugar cane having an inherent moisture content of 85% yielded approximately 89.7% of its moisture content in the preliminary expression cage 10d of the main expression cage Thus, the bagasse had a final moisture content of about 32% with a sucrose content of 5.51%. In a second test using the same press, cane having the same inherent moisture content gave a recovery of 93.1% of the juice with a final sucrose content of 3.89% and a moisture content of 30.0%.

Thus, in passing through the press the cane material will be subjected to intermittently varying pressures by virtue of the fact that the maximum diameters of the compacting collars are greater than the maximum diameters of the screw flight bodies. This feature results in a partial relaxation of pressure while still maintaining continuous expressing pressure as the material clears the rearmost edge of each of said collars. While the precise conditions developed in the expression cage are not fully understood, largely because of the practical difiiculties of accurately determining the pressure and other conditions at a series of points throughout the cage, it is be lieved that the action may be described generally along the following lines. As the pieces of cane are fed for wardiy by the flights on the feed worm portion, they are packed into the first screw flight portion and because of the difference in the rate at which such flights are driven, a substantial pressure is developed on the cane in such first flight. This is accompanied by expression of juice through the screen bars and additional pressure is built up as the material passes over the first collar, and its rotation is interrupted by the breaker bars. This is accompanied also by a mechanical action which results in some defibering and reorientation, with the result that further juice is extracted and the fibers are advanced to the next flight which they encounter with a different distribution.

As the material continues its passage through the cage, it encounters successive interrupted flights alternating with the series of collars and breaker bars so that such crushing, defibering and reorienting occur successively. It will further be noted that the clearance on the last flight between the body of the flight and the inner periphery of the cage is less than that of the other flights, thus resulting in an increased pressure when the material reaches the discharge end. This not only contributes to a higher effective yield but also assures the more thorough working of the material to express the maximum amount of juice therefrom before it is finally discharged.

Since the mean pressure exerted on the cane material is between the pressure created by the screw flights and the pressure created by the pressure collars it is apparent that pressures below the mean pressure are used while the material is being mixed and defibered and pressures above the mean pressure are used when compacting the material to express the juice therefrom. Additionally, the mean pressure is a cendant because of the increased pressures created toward the outlet end of the press.

Although the forces against the material during its passage through the press are intermittently varying, it should be noted that the mean pressure is quite high, probably being in excess of 5,000 p.s.i., so that the pressure against the material is at all times on a high level. Maintenance of the pressure at a high level while it moves longitudinally through the press results in creation of frictional heat which materially raises the temperatureof the cane and softens the walls of the parenchyma cells and fibrovascular bundles aiding the expression of'juice' from the cane. For example, the juice toward the discharge end of the press is atabout a boiling temperature and the discharged bagasse at about 180 F., the temperature of the bagasse probably being greater while in the press and cooling somewhat upon release due to expansion.

As the cane progresses through the press the juice is expressed in the compacting zones and falls into collecting chamber 146 from whence it iscollected in a suitable storage receptacle. Expressed cane bagasse is discharged through outlet opening 140 into collection means separate from the juice collecting means so that no reabsorption of the juice can occur after the pressure is relaxed.

FIG. 7 of the drawings illustrates an apparatus 175, comprising a roller type mill 176 and a screw type expressing press 177, for removing the juice from sugar cane and related sucrose bearing fibrous material. I A conveyor 180 delivers raw cane 181 to opposed crushing rolls 182 which have serrated orotherwise suitably formed working surfaces to break the cane and'deliver it onto a second conveyor 183 with 40% to '70% of the original juice content removed. The juice taken from the cane at this point can be collected in a receptacle 185 for subsequent handling or it can be combined with juice extracted in later operations. The second conveyor, 183, is positioned to discharge the crushed came into thenip @of the millrolls of the mill 176. From mill 176 the cane passes through the rolls of mills 190 and 192 by means of conveyors 191 and 1 93 and is finally delivered onto a discharge conveyor 194 asbagasse having from about 85 to 95% of its sucrose content removed. Fluid expressed from the cane during its passage. through the mills is collected within a tank 195 and from there directed to a suitable point of collection. The recovery of such high percentages of sucrose is made possible by the addition of a suitable maceration liquid, such as water,

to the cane through fluid conducting pipes 200 prior to its delivery to mills 190 and 192. Fluid'can be obtained from a tank 201 which is under pressure from pump 202, the tank being supplied with fluid through an inlet pipe 203.

The bagasse being discharged from mill 192 onto conveyor 194 is dumped into the feed hopper 205 of screw press 177 where it can be supplied with maceration fluid I by means of a pipe 206 in those instances where preferred. Pipe 206 extends from the supply tank'201 to the hopper 205. From hopper 205 the material moves downwardly dropped to 1.93%, these figures representing considerable additional recovery of material from. the mill bagasse. It is alsoimp'ortant to note that the bagasse will have increased fuel value by virtue of the reduced moisture content, a significant featnredue' to'the fact that many mills use the bagasse as fuel for operating the plants.

7 A second run which was conducted using bagasse with a moisture content of 48.75% and asucrose content of 2.78% but adding 500 pounds per hour of maceration water to the material as it entered hopper 205 resulted in a bagassedischarge from screw press, 177 having a moisture content of 37.0% "andfa sucrose content of 2.12%. The addition of this amount of water raised the moisture content of the bagasse to approximately prior to the final expressing and defibering operation which occurs in the screw press.

A slightly modified form of apparatus for subjecting sucrose bearing'materials to expressing operations with the addition of maceration fluid between the two operations is shown in FIG. 8. Here, two interrupted flight screw presses, 210 and 211, are arranged in series so that the discharge opening 212. of press 210 will deliver bagasse .into the hopper .213 of the second press. A fluid reservoir 215, having a pump 216, is provided with a pipe 217 for supplying maceration fluidto bagasse just as it is expanding upon leaving press 210, thus insuring that the bagasse will quickly soak up ofmaceration fluid.

While the process and form'of apparatus herein de a maximum amount scribed constitutes a preferredembodiment of the invention, it is to be understood that thisinvention is not limited to this precise process and form of apparatus and that changes may be made therein without departing from I the scope of the invention which is defined in the appended claims. 7

What is claimed is:

' 1. The process of expressing juicefrom sucrose bearingfibrous material in plants utilizing a roller type juice expressing mill comprising, feeding raw fibrous material into the mill to effect crushing thereof between the rolls and release of juice therefrom,.disch'arging crushed bagasse from the outlet end of said mill, collectingthe bagasse separate from the juice at a location removed from'the material passing throughthe rolls, advancing the collected bagasse to the inlet of an expressing press having drainage openings in the side walls thereof, and feeding the bagasse through the press while exerting a sustained relatively high mechanical pressure on the bagasse to express additional juice therefrom through the drainage openings in the side walls of the press.

- 2. Theprocess of expressing juice from sucrose bear ing fibrous material in plants utilizing a roller type juice expressing mill 'comp1ising, 'feeding raw fibrous material into the mill to effect crushing thereof between the rolls and release of juice therefrom, discharging crushed ba-. gasse from the outlet end of said mill, collecting the bagasse separate from'the juice at a location removed from the material passing through the rolls, supplying maceration fluid to-said crushed bagasse to increase the Table 3 Screw Flights and Pressure Collars i i 86 87 88 89 90 91 92', 93 94 95. 96 Diameters 1n 1nches 5%; 5%6-634 5M6 WAG-6% 5%; {Ms-6% 5M0 5%(3-691 5%: 5%s6% 6% 6% Length in inches 6% 2% 4% 4% 4% 4% 4% 3 ,4 4% 3% 4% 5% In tests conducted at a feed rate of 2% tons of cane through hopper 205 and'press 177, the press being dimensioned according to Table 3,, the, bagasse moisture content was lowered to 33.0% While the sucrose content ,3- The process of expressing juice from the cells of juice-therefrom through'the drainage openings in the side walls of the press. a

sucrose bearing bagasse being discharged from a roller type juice expressing mill comprising, introducing the bagasse into the feed chamber of a screw type press having alternately arranged compacting and defibering zones within an elongated juice expressing cage having drainage openings in the side walls thereof, freeing juice from the bagasse by exerting a sustained high mechanical pressure thereon while advancing the bagasse through the compacting zones, advancing the bagasse through said defibering zones intermediate each of said compacting zones with concurrent reorienting of the fibers contributing to further expression of juice, and discharging bagasse having a moisture content not exceeding 40% by weight through the outlet end of said press.

4. The process of expressing juice from the cells of sucrose bearing fibrous material comprising, introducing the fibrous material into the feed chamber of a first screw type press having drainage openings in the side walls thereof, subjecting the material during its passage through the press to crushing, defibering and mixing actions under substantial mechanical pressure to effect expression of juice through the openings and accompanying lower retention of juice in the material, discharging the fibrous material through the outlet end of the press, adding maceration fluid to the discharged fibers to raise the moisture content to near the original amount, introducing the discharged fibers into the feed chamber of a second screw type press having drainage openings in the side walls thereof, subjecting the material during its passage through said second press to crushing, defibering and mixing actions under substantial mechanical pressure to effect further expression of juice contributing to a high yield, and discharging the fibers through the outlet end of said second press.

5. The process of expressing juice from the cells of sucrose bearing fibrous material comprising, introducing the fibrous material into the feed chamber of a first screw type expressing press having drainage openings in the side walls thereof, subjecting the material during its passage through the press to crushing, defibering and mixing actions under substantial mechanical pressure to effect expression of juice through the openings and accompanying lower retention of juice in the material, discharging the fibrous material through the outlet end of the press, concurrently adding maceration fluid to the fibers as they are expanding upon being discharged from the outlet end of the press to raise the moisture content of the fibers to near their original amount, introducing the discharged fibers into the feed chamber of a second screw type press having drainage openings in the side walls thereof, subjecting the material during its passage through said second press to crushing, defibering and mixing actions under substantial mechanical pressure to effect further expression of juice contributing to a higher yield, and discharging the fibers through the outlet end of said second press.

6. A process for the extraction of sugar juice from sugar cane comprising, cutting the sugar cone into ap propriate lengths, crushing the cut lengths of cane to rupture a substantial proportion of the cells containing sugar and, passing the prepared cane through at least one screw press whereby to extract sugar juice from the crushing cane.

7. A process for extracting sugar juice from sugar cane which comprises rupturing a substantial proportion of the cells containing sugar to produce prepared sugar cane, passing the prepared cane through a series of sets of milling rolls and thereafter through at least one screw press, whereby to effect extraction of sugar juice from prepared sugar cane.

8. In the process of extracting sugar juice from sugar cane which comprises crushing the sugar cane to rupture at least a substantial proportion of the cells of the sugar cane which contain sugar to form the prepared sugar cane, passing the prepared sugar cane through a first set of milling rolls to form first bagasse, adding maceration liquid to the first bagasse, passing the thus treated first bagasse through a second set of milling rolls, and continuing to alternately add maceration liquid and press the resulting treated bagasse until a final bagasse is obtained, the improvement wherein the liquid content of the final bagasse is further decreased comprising passing the said final bagasse through a screw press.

9. A process as defined in claim 6 comprising the additional steps of adding maceration liquid to the material discharged from said screw press, and then feeding the material through a second screw press to express liquid therefrom with the maceration liquid promoting extraction of juice from the material.

References @ited by the Examiner UNITED STATES PATENTS 239,222 3/81 Burgess 100-l17 X 2,061,196 11/36 Hymers 10075 X 2,466,492 4/ 49 Sizer 100-150 X FOREIGN PATENTS 302,185 12/ 17 Germany.

752,485 7/3 3 France.

MORRIS O. WOLK, Primjary Examiner.

WALTER A. SCHEEL, Examiner. 

1. THE PROCESS OF EXPRESSING JUICE FROM SUCROSE BEARING FIBROUS MATERIAL IN PLANTS UTILIZING A ROLLER TYPE JUICE EXPRESSING MILL COMPRISING, FEEDING RAW FIBROUS MATERIAL INTO THE MILL TO EFFECT CRUSHING THEREOF BETWEEN THE ROLLS AND RELEASE OF JUICE THEREFROM, DISCHARGING CRUSHED BAGASSE FROM THE OUTLET END OF SAID MILL, COLLECTING THE BAGASSE SEPARATE FROM THE JUICE AT A LOCATION REMOVED FROM THE MATERIAL PASSING THROUGH THE ROLLS, ADVANCING THE COLLECTED BAGASSE TO THE INLET OF AN EXPRESSING PRESS HAVING DRAINAGE OPENINGS IN THE SIDFE WALS THEREOF, AND FEEDING THE BAGASSE THROUGH THE PRESS WHILE EXERTING A SUSTAINED RELATIVELY HIGH MECHANICAL PRESSURE ON THE BAGASSE TO EXPRESS ADDITIONAL JUICE THEREFROM THROUGH THE DRAINAGE OPENINGS IN THE SIDE WALLS OF THE PRESS. 